MOSCOW (Dow Jones) -- The chief executive of Russian potash producer Uralkali was arrested Monday in Belarus on criminal charges after a meeting with the country's prime minister, heating up a fight over trade of the fertilizer ingredient.

The arrest of Vladislav Baumgertner and a Belarussian threat to seize assets comes less than a month after Uralkali pulled out of a trade partnership with Belarus's state-run potash miner, Belaruskali, effectively ending a virtual global pricing cartel and upending the shares of potash companies around the world.